The present invention relates to endoscopes (including devices such as borescopes, fiberscopes, etc.) and specifically to control of endoscopes capable of varying their direction of view.
Endoscopes are elongated devices used to visualize the insides of cavities. Recent developments have brought about endoscopes capable of varying their direction of view. The purpose of these endoscopes is to allow the user to scan over a larger area with less device movement than traditional endoscopes and provide greater flexibility in obtaining a desired view.
Most endoscopes capable of varying their direction of view include mechanically steered optical components. These are controlled using one or more knobs or similar devices for adjusting the degrees of freedom available in the endoscope along the respective axis of each degree. Examples of these are disclosed in U.S. Pat. No. 3,880,148 to Kanehira et al. (1975), U.S. Pat. No. 4,697,577 to Forkner (1987), U.S. Pat. No. 3,572,325 to Bazell et al. (1971), and U.S. Pat. No. 6,371,909 to Høeg et al. (2002), each of which is incorporated herein by reference in its entirety. In all of these examples, each axis of adjustment is controlled independently. Making a desired compound adjustment involving two or more axes is difficult to accomplish, requiring multiple hands and/or great dexterity.
Other endoscopes capable of varying their direction of view include those disclosed in U.S. Pat. No. 5,954,634 to Igarashi (1998) and U.S. Pat. No. 5,313,306 to Kuban, et al. (1994), each of which is incorporated herein by reference in its entirety. These devices provide a viewed area variably selected from within a wide-angle captured image giving a result similar to those with mechanically adjusted optical components. Like mechanically adjusted variable direction of view endoscopes, these devices may only be adjusted in a predetermined manner with predetermined axes.
Each of the above endoscopes has a set of adjustment axes that define a natural coordinate system for that endoscope. In the natural coordinate system, each degree of freedom of the endoscope is one axis of the coordinate system. Each endoscope is controlled in relation to its natural coordinate system. Due to differences in the design of varying endoscopes, each endoscope's natural coordinate system may be different. This can create a significant problem for users when attempting to work with a different endoscope than that to which they are accustomed. The natural coordinate system of an endoscope is always aligned with that endoscope rather than with the user's surroundings or the operating cavity. The user can become confused and disoriented when trying to selectively scan within a coordinate system that fails to align with a familiar environment.
Because the distal end of a variable direction of view endoscope is generally not visible during use, the user often requires an external indication of the current viewing direction. Some endoscopes fail to have any method of indicating the direction of view, while others include indicators that are inconvenient or difficult for the user to interpret. Not knowing the current direction of view makes it challenging to adjust to a desired direction of view or find a particular feature within the cavity. Additionally, returning to a previous direction of view can be quite challenging.
Although prior art variable direction of view endoscopes may have been designed for easy and efficient use, the interfaces heretofore known suffer from at least the following disadvantages: a) the interface provided with each endoscope can be unintuitive and confusing for the user; b) the disjoint control of multiple degrees of freedom makes precision compound adjustments prohibitively difficult to execute; c) various types of variable direction of view endoscopes require very different methods of operation; d) the control coordinate system available can not usually be aligned with the user's surroundings; e) the control coordinate system available can not usually be aligned with the operating cavity; f) the current direction of view can be difficult to determine; and g) the user must manually adjust the endoscope to return to a particular direction of view.
Some endoscopic control systems include actuators such as motors to assist the user in controlling the view. For example, U.S. Pat. No. 5,524,180 to Wang et al. (1996), which is incorporated herein by reference in its entirety, discloses a motorized control system for automated positioning of an endoscope. Such control systems utilize a computer and robotic arm to control the movement of an endoscope for the purpose of changing the viewing direction. However, instead of moving the entire endoscope, variable direction of view endoscopes should be controlled in a way that utilizes their internal direction of view adjustment systems. Therefore, existing electro-mechanical endoscope control systems are not well suited to situations in which the use of a variable direction of view endoscope is desired.
Accordingly, the primary object of the present invention is to provide an easy-to-use interface for a variable direction of view endoscope capable of adjusting multiple degrees of freedom of the endoscope simultaneously to execute precision compound adjustments. Another object of the present invention is to use this interface to mask the specific implementation of the endoscope from the user through a standard set of displays and controls. Yet another object of the present invention is to provide an interface having several different control coordinate systems for the user to choose between, enabling more efficient and effective procedures.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as more detailed description is set forth below.